Solving the optimal control problem with a free final time, such as suborbital launch vehicle (SLV) trajectory optimization with two control variables and multi-constraints ones based on particle swarm optimization (P...
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Solving the optimal control problem with a free final time, such as suborbital launch vehicle (SLV) trajectory optimization with two control variables and multi-constraints ones based on particle swarm optimization (PSO), the smoothness of control variable can not be satisfied by linear interpolation method. A novel method including some improving strategies based on PSO for trajectory optimization is proposed, named LCPSO which is a kind of Cooperate PSO based on Legendre orthogonal polynomials. An additional control variable is introduced and transcribes the original optimal problem to a problem with fixed final time, and one dimension searching method based on interval analysis is used to optimize the additional control variable. Furthermore, a theorem on how to find the boundaries of the coefficient of polynomials is proved. Compared with basic PSO, LCPSO has traits of lower dimensions and smoother control variable. An example of trajectory optimization shows the effectiveness of the LCPSO algorithm.
Combining with the lαβ color space and the nonsubsampled contourlet transform (NSCT), a novel fusion algorithm for infrared and color visible images based on the color transfer and information entropy was proposed. ...
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Combining with the lαβ color space and the nonsubsampled contourlet transform (NSCT), a novel fusion algorithm for infrared and color visible images based on the color transfer and information entropy was proposed. Firstly, the R, G, B bands of the color visible image were averaged and then the intensity component image was attained. Secondly, the attained component image and the infrared image were merged based on the NSCT and then a grayscale fused image was obtained. Lastly, a color transfer method based on the lαβ color space was employed to transfer the color information of the color visible image into the fused grayscale image and then the final fused color image wss attained. When the grayscale visible image and the infrared image arefused, according to the physical characters of the infrared image, a weighted averaging scheme based on the local area mean and local area information entropy was proposed for the lowpass subband coefficients. As well, according to the distribution differences of the noise and the geometric characters of the image in the NSCT domain, a selection principle based on the local area direction entropy and the local area energy was proposed for the bandpass directional subband coefficients. Experimental results demonstrated that the proposed algorithm not only can extract the abundant background information of the visible image and the target localization information of the infrared image, but also can make the fused color image maintain the nature color information of the visible image as much as possible.
3D simulation of an ERT sensor field is established using COMSOL and MATLAB 7.0 to study the limitations of an ERT system's sensor field and determine the influence of electrode size and geometry on the establishe...
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A new structure of capacitive sensor used for an automatic car-wiper system is presented. It aims to develop a low-cost sensor with high sensitivity and robustness. The working principles of the sensors used for liqui...
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A passive universal image steganalysis method is proposed that is shown to be of higher detection accuracy than existing truly blind steganalysis methods including Farid's and the WAM. This is achieved by improvin...
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A passive universal image steganalysis method is proposed that is shown to be of higher detection accuracy than existing truly blind steganalysis methods including Farid's and the WAM. This is achieved by improving some weaknesses of Farid's steganalysis scheme in feature extraction, that is, instead of deriving an over-determined equation system for each sub band of the wavelet decomposition, the sub bands are divided into overlapping blocks and an over-determined equation system is constructed for each block. To guarantee the existence of finite answers, the over-determined equation systems are solved in a way different from Farid's by using Moore-Penrose pseudo-inverse concept. Further improvement to the performance is achieved by adding diagonal directions and increasing the number of moments. The comparative evaluations confirm the superiority of the proposed method over prevalent blind steganalysis schemes.
The contourlet Transform is an efficient directional multiresolution image representation, but it is not shift-invariant. The nonsubsampled contourlet transform (NSCT), is a fully shift-invariant, multiscale, and mult...
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Cognitive radio is used for enhancement of spectrum *** many works have been accomplished on the power allocation of cognitive radio,limited efforts have considered evolutionary *** this paper,we study this problem in...
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Cognitive radio is used for enhancement of spectrum *** many works have been accomplished on the power allocation of cognitive radio,limited efforts have considered evolutionary *** this paper,we study this problem in the cognitive radio networks where interference constraints are defined for protection of quality of service(QoS)for both primary and secondary *** defined as functions of the signal-to-interference-plus-noise ratio(SINR) are matched for each secondary user which meets Nash’s *** general,the region of utilities that meets the constraints is *** is possible to make simplifications,generate a convex region,and then use common convex optimization approaches to obtain a ***,Particle Swarm Optimization(PSO)does not need such simplifications and thus its results are superior to those of the convex optimization *** is an evolutionary algorithm based on social intelligence,utilized in many optimization *** is a global optimizations algorithm that does not require the objective function be differentiable as required in classic optimization methods.
3D simulation of ERT sensor is established with multi-physical coupling software COMSOL and MATLAB7.0, analyze the limitation of ERT system 3D sensor field and deeply study the influence on the established fields by s...
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An image watermarking scheme resisting RST (rotation, scaling, translation) based on RST invariant square region is proposed in the paper. Two SIFT (scale-invariant feature transform) feature points are selected to de...
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Traditional interest points based image retrieval methods employed local features of interest points to describe image. The difference between local areas of interest points and the region of interest limited the retr...
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